Decorative and protective bodyside moldings formed at least in part from thermoplastic materials are known in the art. Bodyside moldings protect, e.g., vehicle doors, and provide an aesthetically-pleasing appearance. Such moldings may be formed by injection molding and/or extrusion processes.
To form bodyside moldings by an extrusion process, generally one or more continuous, pliable, thermoplastic melt streams from suitable extrusion dyes are introduced into a forming tool which molds the melt stream(s) into a continuous extrusion having a desirable cross-sectional shape. Bodyside moldings are then cut from the continuous extrusion after the extrusion has sufficiently cooled. In one such process, a base layer melt stream is co-extruded along with an upper "show" surface layer having a desirable, aesthetically-pleasing appearance. The show surface material may be of various materials suitable for the extrusion process, including Mylar, chrome or a show thermoplastic graded material.
FIG. 1 illustrates a representative vehicle 3 including decorative bodyside moldings 5 thereon. Each of components 5a, 5b, 5c, 5d and 5e, mounted on respective body portions of the vehicle, represents a bodyside molding. Specifically, bodyside molding part 5a is mounted on front door 7, bodyside molding part 5b is mounted on rear door 9, bodyside molding part 5c is mounted on the fender rearwardly of the front wheel well, and bodyside molding parts 5d and 5e are mounted on the corner panel, forwardly and rearwardly, respectively, of the rear wheel opening of the vehicle.
FIGS. 2-3 illustrate a conventional bodyside molding, including molding body 9 having a hollowed interior, bolt 11, bolt mounting section 13, and seating body 15. As illustrated in FIG. 3, this bodyside molding is to be attached to vehicle 17 by way of bolts 11. As discussed in U.S. Pat. No. 5,639,522 (hereby incorporated herein by reference in its entirety), the bodyside molding of FIGS. 2-3 is manufactured utilizing a hollow injection molding process.
Because bodyside moldings are designed to be aesthetically pleasing to the eye, it is often desired to chrome-plate such moldings. It is known to manufacture hollow one-piece chrome-plated bodyside moldings using a gas-assisted injection molding process as follows. Initially, a flowable material such as TPO (polyolefinic thermoplastic resin) is injected into a dye of an injection molding apparatus. Thereafter, a gas pin is inserted into the material within the dye cavity so as to allow gas (e.g., nitrogen) to be shot via the gas pin into a central portion of the material. The gas causes the flowable material to proceed/move outwardly within the dye against the edges thereof so as to form a hollowed-out piece. The gas pin is thereafter removed from the piece. Upon cooling and removal from the dye, the result is a bodyside molding component. However, this bodyside molding component has a hole or aperture defined therein due to the gas pin which had been inserted through a portion thereof in order to allow the pressurized gas to be introduced.
The molding (including the hole therein) is then processed through numerous liquid/metal baths in order to chrome-plate the same. For example, the molding may first be dipped into an acid bath to prepare its surface to accept metal to be applied in a subsequent bath(s). After removal from the acid bath, the molding is rinsed in a bath and thereafter dipped into an electroplating bath such as a copper or nickel bath. After removal from this copper or nickel bath, rinsing may again occur in another bath, with the molding thereafter being dipped in a chrome bath for electroplating the molding body with chrome. In short, a plurality of baths are utilized during the chrome plating process, with the bodyside molding being moved from one bath to the next in serial fashion as the process progresses.
Unfortunately, the hole in the molding due to the gas pin described above is problematic. This hole tends to collect materials from the different baths used in the electroplating process (e.g. liquid/chemicals from a bath can either collect in the hole itself or seep into the hollow interior of the body through the hole) which ultimately can lead to bath(s) contamination. For example, the hole may collect acid from the acid bath. Upon removal from the acid bath, acid therefrom is located in the hole itself and/or within the hollow interior (i.e., cavity) of the molding. The rinsing process may thus not be able to effectively remove all/most traces of the acid from the hole and/or cavity of the molding. As a result, when the molding is subsequently placed into another bath during the chrome plating process (e.g., a nickel bath, copper bath, and/or chrome bath), contaminates from earlier bath(s) may make their way thereinto causing bath contamination. In other words, later baths or tanks in the electroplating process may become contaminated due to the tendency of the hole-inclusive molding to collect and transport materials from one bath to the next during the process.
It is apparent from the above that there exists a need in the art for a bodyside molding which may be manufactured in a manner such that the likelihood of bath/tank contamination is reduced during the chrome-plating process.
This invention will now be described with respect to certain embodiments thereof, accompanied by certain illustrations.